Nice unit but pretty lean in stock form, not rich. Sucking air around the throttle shaft would only make is leaner and smell more in the exhaust, not rich.
I would NOT install larger jets, instead I'd recommend using my full tapered 45 primary rods and smaller jets, plus one of my rebuild kits with a high flow N/S assembly and lifetime warranty accl pump. It will enjoy opening up the idle system just a tad even for a stock engine build.
When you get time call me at the shop, I'm here 7am-4pm, Monday thru Thursday EST.....tks.....Cliff